Controller for electric motors and similar devices.



H. W. LEONARD.

CONTROLLER FOR ELECTRIC MOTORS AND SIMILAR mzvmns APPLICATION FILED MAY 17, 1907. BEHEWED JULY 18. 1910.

Patented Nov. 4, 1913.

w 5M INVENTOH lT/VESSES /4/z./4UL.

a a 1 g 2 h ATTORNEYS.

UNITED STATES PATEET ()FFICE.

BARRY WARD LEONARD, or BRONXVILLE, NEW YORK.

CONTROLLER. FOR. ELECTRIC EOTGES AND SIXILAB. DEVICES.

ori inal application filed July 11, mos, Serial no. 165,061. Divided and this application filed may 17,1907,

Specification Letters Patent.

PatcntcdNo'vn,1913.

Gerbil no. 74,150. Renewed July s, 1910. Serial no. 572,521.

T 0 aa whomit may concern:

- Be it "known that I, Hirer Wane Leon- ARB', a citizen of the United States, residing at Bronxville, inthe county of Westchester 5 ahd'stabeof New York, have invented certain new and useful Improvements in trollers for, Electric Motors and Similar Devices, ofwhic'h the following is a full elear,

" and exact specification.

This flpb ication-is a diyisionof my pending application for improvement in controllersfor electric motors and similar devices,

' filed Joly:-1-1',.19fi3, Serial No. 165061, on

-;Pa'tent No. 855,897, was

June 4.1907.

f My invention relates principally to the deviceseniblo ed for starting and. regulating the .0 electric motors, and to the de- -vices employed for protecting such devices and the motor against damage due to abnormal variationsin the circuit. Heretofore such devices, and particularly the starters fieldcontrollers, were preferably enpieces'of apparatus and were operated independently of each other. Such operation.- -of the. devices and .to carelessness or ignorance on the part of the operator.

One object of my invention is to comb ne a. motor starter, speed regulator and automatic protective devices with interlocking 85 means, vwhereby" the several elements constituting a controller can only be operated in the proper sequence to start and regulate a motor. and so that the protective devices will always be in a position to respond to abnormal changes inthe motor circuitg'and whereby the startingof a motor and the control of its speed will be fool proof;

that is to sayithe controlling apparatus and the motor will be entirely safe. even in the 51 hands of inexperienced, careless or ignorantoperators.

In the operation of many kinds of machine tools and other appliances by electric motors, it is very desirable that there be pro ..vided a simple, ellicient, .reliable. inexpensive and compact formof controlling appa- .ratns by nicans'of which the motor can he started and brought to full speed. and later. iif necessary. operated at any speed over as 55 wide a'range of speed as possible. On ac- Concount of the efiiciency and simplicity of the method, it is very desirable to secure the speed variation by varying the field strength of the motor. Electric motors have now been so far improved as regards freedom from sparking, that they require very little attention in operation even when the held is varied over a very wide range, and hence in the-future these motors will be. very extensively employed in the operationof machine ,tools and in performing many other kinds of work where a wide range of speed is of value, and'especially where the torque varies inversely'as the speed to such an extent that the power of the motor is more or less constant. The controlling apparatus for such motors should have the following characteristics: First. an overload protective device which will positively and instantaneously open the circuit to the'inotor if under.

any conditions of starting 'or operation a curiient greater than a certain predeterminable amount should flow in the motor circuit. Second, this overload device. must be such that the motor can be safely and simout loss of time and without expense. Third, a no-voltage release or'electro-responsive device which will automatically act if the supply voltage fails, or is reduced to a very low point, to protect the motor against" the risks due to a sudden rise to full voltagei and such no-voltage device shall be dependent upon the volts upon the motor armature and shall be independent of any current through the motor. Fourth, a device by the manipulation of which the operator can readily change the spcrd of the motor gradually and over a wide range. so that, for example a cutting tool can he worked in the most efiicient manner atany speed and out within the capacity of the motor. Fifth. a starting rheostat. Sixth. interlocking or functionally related mechanism, or equivalent arrangement of mechanism, which will insure the proper sequence of adjustments. and'whcrehy it will be impossible for the operator to start the motor while (he molor has an improperly.wcakened field. While V '80 ply started up again by theoperatpr 'withcurrent passing through the motor armature, such as a switch in series with the motor armature andstarterl My invention is illustrated I in the accompanying drawings, in whichi a Figure 1 is a diagram illustrating one form of my invention, Figs. 2 and 3 are dia grains of modified forms, and Fig. 4 is a deto arever sing cont-roller andin which the tail view of a yieldable section of a part of the structured-Fig. 2enlarged.

' In Fig.1 my-lnven'tion' is 'shownapplied reversing controller and field rheosta't are functionally related so that the resistance of the controller cannot be cut out except when the ,field- -i'sin a certain condition.

The armature .arid field winding of the motor is, indicated at In the main circuit is a switch comprising the two spring pressed arms A, B, the current passing from one supplylterminalthrough the over.-

load solenoid D, which may act to release arm'B'and open the circuit, then through arms' B and 'A through the reversing con-' troller and motor armature to .the other sup ly terminal. Current also passes'inde pen ently'froin one side of the line through. the resistance R and retaining magnet E to the'other side,-and there is likewise a circuit across the line including the field of the motor, the field resistance 0 andjhe field rheo-- staturm 0*. The movable element/of the "reversing controller: comprises an arm A:

elect-ricallyconnected to onejside the line and engaging one or -the .other of two contact segments 1 connected-.-to' the.jte'rri iinalsofthe motor armature'x'iThe 'movabief ele,-v

ment' also includes an insulated 'foadacti 'one end--of-a. rod- 0 {connected-to the field" -rheost-atarrncfla'spring'son arm a. tending to force the 'rod'againstthe cam. The

position of the arm c 'is' consequently determined by the positionfof the reversing osition' of the con-f.

portion 10' which 'electrica 1y 'conn'ecbfthe contact segmental-with the concentric outer strips and the contact im" of the control-j ling resistance. The-operating shaft of the controller carries. a'cam n on which rides controller, The f oflf trollefiarm is a vertica one with-the part k downward. Suppose-the circuit breaker to vbe closed and that: the controller-arm is turned from the oifposition so that the part:

kfengages the contacts at the right. The

current will then. pass from say positive line to'right-hand segmentm, through the armature resistance to art It se ment I p 7 a 4 a motor armature, left-hand segment'l, arm k to negativeline. As the arm is i otated'left handedly, the ar'inature resistance will be gradually cut out and. will beall out out' when k en ages segment m. During this .''operation, t e rod 0 has remained at its lowest position by pressure of spring a and all field resistance has therefore been-cut out giving a strong field. Upon further movement of the controller, the rod 0 rides upon an inclined portion of camn, causing field resistanceto be gradually cut in giving a further increase in the Speed of the motor.

This condition is illustrated in the figure.

posite direction giving reversal in rotation.

F urther-niovement' ofthe controller arm cuts out the armature-: iesistance while the" field is maintained at' full strength and af-. t er-ward weakens the field as previously ex"- plained. p

In Fig. 2, I have shown-a reversing controller, field rheostatandcircuit breaker all functionally related so that circuit breaker cannot be fcl'osed except when the reversing controller in proper condi tion and the resistance oft-he reversing com ,troller cannot be cut out erceptwhenlth e field rheostat is in roper condition. 1 have shown a double p0 e circuit breaker. having spring pressed independently movable arms each adapted to be; held in position by me-[ "chanical restraining means, as bylatches t.

'The armsare released. by the upward move- .ment of the'icore. of'the,overloadsolenoid;

D',.or t he left hand arril "p'is releasediby the fall of the core of the no-voltage'solenoid-E with'a: resistance R; The reversing conwhich' is connected across th'eline in series Z troller is. shown as madeup ofthe two conf 5 tact segments land two outer ser es of're sistancefcontactsv rtfi over whichniov'es the controller armjcomprising the part 70 which contacts with segments l'and is; connected to one side of the line, and" the part k.wh1ch' -makes a connectionfrom segments l to the contacts in. The segments 1 are connected.

to the m tor armature terminals and the t upper contacts 111/ to one. side oftheQ-line.

Mounted uponthecontroller shaft is afcir-- cular plate havin a q in one'pa'rt thereof. Z A rod 0 'is forced against said plate as by a spring It" and carries a-projfec tion 0 adapted to engage a notch 12 in one of the circuit breaker arms ,pq'The rod 0" has 'a yieldable' section as" indicated l at 0'v similar to that' shown in Figs. Sand t of'my said oi'i 'halapplication a'n'd ias shown in Fig. 4'0 this case. Mechanically connected with theshaft of the reversing controller,

plate 9 having a notched'portiongt- This in which has a yieldable portion o and is as by t! 2 extended shaftw isa'ci-rcular' notch is adapted to receive one end of a rod' troller, fieldrheostat' and circuit breaker.

The circuit breaker is shown in the form :ot: a pivoted switch B, spring vpressed I'liyi spring-sat its pivot so as to tend to: move t switch to open the main circuit aticorilower end-of the rod engages a plate having an inclined notched portion g This plate is mounted on the shaft of the field rheostat controlling a. The parts-are shown in their open position-and the arms of the circuit breaker are fnee'to .be closed and the reversing rheostat maybe operated since the field resistance is all cut out of the field circuit. It, howevor, the reversing 'rheostat were in any other than elf position,

the rod 0- would the/notch of plate 9 and projection o woulcl engage the notch o preventing the closin' of onezarm of the circuit breaker. Also i 'rbhe field re .sistancearm were many-position other than that in which, resistance is the rod :2: would be and engage the notch Q preventing the movement of the reversing cont-roller to start the "motor unless the 'fieldhas its hill-strength Therefore the circuit breaker cannotbe cl0sed unls s the reversing controller is inoff position and the circuits of-the reversing controller cannot be closed unless the field resistance is out of circuit. Starting with the armature resistance in, and the field resistance out, is consequently imperative. When the reversing controller is turned in one direction from oil position, current passes through the armature in one direction and the armature current- .is reversed by turning the reversing C such that red 0 remains in its lowest posicontrollerin the opposite direction.

I In Fig. 3' I have also shownan interlocked or functionally related reversing contacts y. -A piv0ted latch d tends-normally to engage the pin d when the switch is in the closedposition and to hold the same closed; ,A-cplunger for tripping-thelatch-is Shawn as having two .iron'cores. acted upon by the coil E which-toxins a circuit across the line in series with a, re-,

sistance B through. switch B"v and contacts 3 and normally tends to hold the plunger up and which, upon occurrence oi nc-voltage, permits the plunger to Ml and trip the latch d circuit and which upon the occurrence of overload is adapted to draw the plunger down to trip latch d and open the circuit.

The reversing controller is provided with the contact-segmentsl, l, the contact se 'ments m, and'the resistance contacts m; T e controller arm rOv-ided with an insulated conductor in a aptedsto engage segments Z and the plate 'Z' and: also provided with an insulated conductor k adapted to connect the segments Zwith the segments m or reand allows the circuit breaker to be opened byspning s. other core is acted upon by coil D in-series in the mam sistancc contacts m. The controller arm in the position shown, which is the oil position, engages an extension B ofswitch B so as to close the latter. The plate Z is connected to one supply line and the segments m are connected to the other supply linethrough switch B and contacts y. T he segments Z are connected to the armature terminals.

The motor field coil is shown connected across the line in series with a variable -resistance Er'and arm 0 The arm 0 is pressed by a spring 8 tending to return it to such a position that no field resistance is included and also tending to press the rod 0 which is attachedto arm (2, against a cam n. The cam 12, is attached to shaft w which is also the shaft of the controller arm. The shape of cam n is such that in the off position of the controller, rod 0 is in its lowest position and all field resist-ance'out of circuit.-

When the controller arm is moved in one direction the armature circuit will be closed through the starting resistance and when the circuit is first closed the switch B will be free to open automatically upon occurrence of overload or no-voltage since the controller arm will not then engage the projection 'B". As the controller arm is moved, the armature resistance will be gradually cut out and will be entirely out out when k makes contact with one of the segments m. Up to this position the shape of cam n is tion, but 'upon further movement of the con trol-ler arm, the rod o'will be raised and re sistance cut in the field circuit. When the controller arm is moved in the opposite dixectiom a similar action will take place except that the current through the motor armature will be reversed. It is therefore apparent that if the circuit breaker opens, it can closed and the motor'started again only by first returning the controller arm tooil position and when the arm is returned toofiposition, all field resistance will be cut out In the motor may have a series winding on the field so that the field will be afi'ected by the-armature current.

Although I have shown specific forms of my invention herein, my invention may be embodied in various other forms of construction, and it will be understood that my invention is' not limited to the precise forms hereinshown and described. My invention is also capable of use with currents of di-f ferent 'forms and with various'types of motors, such as motors of direct 0 charnating current type.

Having thus described my invention, I

.declare that what I claim as new and desire to secure by Letters Patent, is,-

1. The combination of independently movable means for controlling the field and armature circuits of an electricmotor, one of said means being adapted to reverse the directionof rotation of the motel-and also. vary resistance in series with its circuit, and means functionally relating the said independent controlling means whereby improper operation -of the said two controlling means relatively toieachjother is pr'evented.,

2. The combination of. an electricmotor, a revtlrslng rheo s tat for varying and reversmg the current in one e1" nent of theimotor; correlated rheostatic means-for controlling the currentin the other -element of the :moto'r, and an electroaresponsive protective device energizedby-acurrent independent of that in the mo toriarmature offield cirwitv 3; Thecombinatipii ermelectric f-mdtor, a circuit breaker, a reversi ig controller, a field rheostat,.andmeansiofpreve the circuit breaker from being close except when the' reversing controllenyis yin its proper position and; for preventing theresistance of the contreller from -being cut out.

e cepawhearae ifield-f-rheostat in its proper position.- a

4; The combinationigfiaiiaeleftric motor,

I a reversing 'sivitch for reversing the current in" one elementofi saidf-moton' means in the circuit of the other; element of the motor t for afiecting-the currehtin said circuit, and;

means for functionally .relatingsaid switch and said first named means.

5.The combination of an electric motor, acontrolling resistance in series with the armature and a difiere ntfcontrolling resistance in series with the field Twindin each of said resistances having a cooperating 'movable. element-and at least one of said movable elements being movable indepe iid entlyof the other, two 'switchesiin serie with each; other and. with said armature, and meansprotectively correlating said two switches and at least one ofsaid switches to and controlling means comprisinga movable element for reversing the armature -'connec;

tions and for inserting resistance in-series with the armature, and a second movable element protectively 'related .to said first named elementfor varying the motor field strength.

8. Thecombination of an elec tric motor, and controlling-means comprising a movable tromotive force applied to one elemental Winding of the motor and a second movable element protectively related to said first named element for varying the electromewinding of the motor.

9. The combination otan electric motor, controlling means comprising means for varying and reversing the electromotive protectively related means for-varying the motor field strength.

10. The combination-of'an electric motor, two -.automatic switches in series with each switches being adapted tobe independently or simultaneously opened upon overload. through the motor. arma'ture,-and means for varying and reversing thef-current in the strength. v

' 11'. The combination 'of. an electric motor having a field winding energized independ- (ently ofits armature current, two independf ently manually closable switches in series 90 i with each otherand with the motor armature,

said switches if theother. be. closed so as to cause an overloa.d,'a reversing rheostat for-- the elemental windings of the motor, and a functionally connected rheostatic element mental winding of the motor.

two independently closable automaticallyopenable switches, in series with each other and with the motor armature, a, reversing switch also'in series in the circuit of, said trolling means. protectively related to said rcveisi'ng switch.

and controlling meanscomprising four-in- .nicnts, one being an armature current reverslng element and one being a field varyin -element, said reversing element and ficl varying element being protectively related.

and controlling means comprising four independently movable circuit control'lingelementsfone being an armature current reversing element and one being a field varying varying element being protectively related,, ca'nd the other tv'o elements being automaticallTTespo'nsive to overload current.

automatic switches in series with each other and with the'rmotor armature, said two switches being protectively related to each element for varying and reversing the elective force applied to the other elemental force applied to themotor armature, and

Yother and with the'motor armature, said means for automatically opening each of varying and reversing 'the current in one of for varying the current, in the other elc- 13. The combination of an electric motor,

15. The combination of an electric motor, U and motor controlling means comprising two 125 motor'armatureand for varying its field 85" 12. The combination of an electric motor,.1 00

switchesand motor armature, andfieldcon- 195 dependently movable circuit controllingelc- 11o 14. The combination of an electric motor,

element, said reversing element and field ,an armaturerere sing switch, an a overload circuit breaking switch preterit related thereto as regards its closure, a motor field :r'heostat, and means protectively the motor; independently of a variation relating said rheostat to one of said switches for insuring proper motor field strength f i when the motor is started 18. The combination of'an electric motor, a no voltage and-overload circuit breaker, a reversing switch, said switch and circuit .breakerbeingin series with each other and with themotor armature, and means for protectively relating said circuit-hreaker-and switch as to the establishm'entof the motor ":1 starting current." A

19. The'eombination of an electric motor,

electromotiveiforce applied to the motor armat and means for varying the field strengih the armature current, and protective means responsive to no voltage and to overload current through the motor armature.

20. The combination of two independently ..f .c1osable switches, means for causing each of said swltches to be automatically responsive to overload and at least one automatically responsive to no voltage, and a protectively related reversing circuit controller in series with said switches.

1 21. The combination of a movable circuit controlling element, means for causing said element to be automatically responsive to no voltage, and a protectively related reversing circuit controller.

22. The combination of an electric motor, a field rheostat, a reversing motor armature rheostat, and means for protectively interloclc'ing said rheostats.

23. The combination of an electric motor, areversing motor armature rheostat, a. no-- voltage and overload circuit breaker, and

Copier of this patent may be obtained for live cents each, by adzessing the Comnn an electric n'iotor, switch, a motor controlling rh est-ah, an auton'n-itic circuit breaker, and roteceively relating means for insuring that the field rheostat is in a po? when reversing the motor said rows-sing switch. 26, The combination an electric motor having winding energized independently of its armature current, and means for varying the voltage and reversing the direction of rotation of the motor comprising a variable-"resistance in series with the motor arinatnre, a variable resistance in series with the field winding, and means for insuring a definite sequence in variation of said resistance when accelerating the motor.

27. The combination of'an electriemotor having a field winding energized independently of its armature current, areversing s itch in series with one of the motor windings, an overload circuit breaker, and means for insuring that the circuitbrealrer can be closed only when the reversing switch is open.

28. T he combination of a. eiectric motor, a switch, mechanical restraining means for said SWiiCll, electro-rcsponsive means comprising two windings one responsive to no- HARRY YARD LEQNARD.

Witnesses:

Hnnnrrrrn D. LEONARD, CAROLYN G.- LEONARD.

- Washington, D. G.

voltage and the other to overload for 0011-. 

